Aðlögunarhæfni fæðunáms hjá afræningja efst í vistkerfi hafsins, háhyrningi / Adaptability of foraging strategies of a top marine predator, the killer whale - verkefni lokið
Fréttatilkynning verkefnisstjóra
The extensive amount of data generated within this project covered multiple aspects of the behavioural ecology of Icelandic killer whales that created an unprecedented degree of new knowledge on this population.
The project titled ‘Adaptability of foraging strategies of a top marine predator, the killer whale' aimed to understand intra-population variability in the foraging strategies of killer whales, specifically by comparing killer whales observed in overwintering and spawning herring grounds. Few studies have focused on this top marine predator, despite the fact that these whales are known to occur regularly in Icelandic coastal waters and thought to specialise upon the Icelandic summerspawning herring.
Heiti verkefnis: Aðlögunarhæfni fæðunáms hjá afræningja efst í vistkerfi hafsins, háhyrningi / Adaptability of foraging strategies of a top marine predator, the killer whale
Verkefnisstjóri: Filipa Isabel Pereira Samarra, Hafrannsóknastofnun
Tegund styrks: Rannsóknastöðustyrkur
Styrkár: 2012-2014
Fjárhæð styrks: 16,74 millj. kr. alls
Tilvísunarnúmer Rannís: 12024804
This project provided the first assessment of the Icelandic killer whale population. It was found that feeding strategies include the year-round production of unique acoustic signals used for prey manipulation, and differences in these signals seem to be related to individual/group variation, not to differences in prey behaviour. Individual/group-level variations in movement patterns and feeding preferences were also observed. For example, some individual whales occur regularly in Iceland but only in the winter and move to Scotland in the summer, presumably to feed on alternative herring stocks or other prey. In addition, not all individuals appear to follow the Icelandic summer-spawning herring migration, suggesting they may target this prey only seasonally or opportunistically.
Further support for variability in feeding strategies was obtained by using diet assessment through stable isotope analysis of small skin biopsy samples. These results challenge previous suggestions that killer whales observed in herring grounds in Iceland are exclusively herringspecialists that follow the same fish stock year-round. The extensive amount of data generated within this project covered multiple aspects of the behavioural ecology of Icelandic killer whales that created an unprecedented degree of new knowledge on this population. The results suggest population structuring, which has significant impacts on our understanding of the role of killer whales as top predators in the Icelandic marine ecosystem. This data will be part of a continued population monitoring effort, with the ultimate goal of improving our understanding of the status of Icelandic killer whales, their role in the marine ecosystem and their ability to deal with future ecosystem changes such as changes in prey availability.
List of project outputs
Journal articles
Richard G, Filatova OA, Samarra FIP, Fedutin ID, Lammers M and Miller PJO (in review) Diel variation in Icelandic killer whale foraging and acoustic behaviour.
Marine Biology
Samarra FIP, Deecke V and Miller PJO (in review) Low-frequency sounds produced by Northeast Atlantic killer whales (Orcinus orca). Journal of the Acoustical
Society of America
Filatova O, Samarra F, Deecke V, Ford J, Miller P and Yurk H (2015) Cultural evolution of killer whale vocalizations: background, mechanisms and consequences. Behaviour, 152(15): 2001-2038. doi: 10.1163/1568539X-00003317
Filatova O, Miller P, Yurk H, Samarra F, Hoyt E, Ford J, Matkin C and Barrett-Lennard L (2015) Killer whale call parameters are similar across the oceans, but vary across sympatric ecotypes. Journal of the Acoustical Society of America, 138: 251-257. doi: 10.1121/1.4922704
Samarra FIP and Foote AD (2015) Seasonal movements of killer whales between Iceland and Scotland. Aquatic Biology, 24(1): 75-79. doi: 10.3354/ab00637
Samarra FIP (2015) Variations in killer whale (Orcinus orca) food-associated calls produced during different prey behavioural contexts. Behavioural Processes 116: 33-42. doi: 10.1016/j.beproc.2015.04.013
Foote AD, Kuningas S and Samarra FIP (2014) North Atlantic killer whale research: past, present and future. Journal of the Marine Biological Association of the U.K. 94(6): 1245-125. doi: 10.1017/S0025315414000800
